Jump to content

Sign in to follow this  
ggunder

Need Brake Booster

Recommended Posts

I have the classic symptoms of brake booster leakage:

Rock hard pedal

Hissing sound on braking

Engine idle increase when brakes applied when parked

The problem is I cannot seem to locate a rebuilt unit! I have tried NAPA, Autozone, O'Reilly and Rockauto. The only help I got was an offer to take my booster and rebuild it.

Any ideas out there?

Thanks!

Share this post


Link to post
Share on other sites

What car? Last time I looked Rockauto had the larger 240Z boosters available...

C

Share this post


Link to post
Share on other sites

As stated earlier, Rockauto has a Centric Power Brake Booster.

Edited by SteveJ

Share this post


Link to post
Share on other sites

Thanks for double checking Rockauto for me. I just placed an order. The Cardone rebuilds are done on the basis that you send your core in for rebuilding, so I imagine that would take more time.

Share this post


Link to post
Share on other sites

Core exchanges are usually after the fact - you get the new one then send in your core for a refund of the core charge. You don't have to send in your core if you don't want to, sometimes the cost to ship it back is greater than the core charge.

Share this post


Link to post
Share on other sites

Two different O'Reilly brick and mortar stores told me they don't stock and couldn't order a booster for my '73 this last weekend....... they could only send mine off to be rebuilt with a 6-8 week turnaround. However, their website had it listed as "in stock" and I ordered one up... it shipped this morning. :D

But that's a late style 8.5" booster for my '73. I heard they interchange fine, but only if you slot the holes in your firewall for the different bolt pattern.

Share this post


Link to post
Share on other sites

Well, the Rockauto part arrived today and it is an 8 1/2 inch diameter unit instead of the 6 1/2 inch unit I wanted. My car is a 1972 model and I think the smaller unit is original. I e-mailed Rockauto to see if they could send the smaller unit since the bolt pattern is different. I guess I will start researching how difficult it would be to retrofit the larger booster to my car, but I am not too excited about that due to the reinforcing plate in the firewall is not too much larger than the existing mounting holes.

Share this post


Link to post
Share on other sites

I believe the original holes were on 8cm centers (width) where the new ones are on 10cm. (height spacing is the same) It is easy to drill but on a 1970 you must also drill all holes ~ 0.5 to 1cm lower to clear the bell arm bracket and the clutch slave. A 72 may not have this problem. Try a mock-up cardboard disc first.

Oh yeah.... the bigger booster was a great improvement!!!

Share this post


Link to post
Share on other sites

Blue, are you serious about the performance improvement or just poking some fun at small design changes that don't accomplish much except to make buying parts more difficult? It looks like four new holes that are each 1 cm outboard of the old holes would do the trick. It is hard to say, but I think the right hand holes would be nearly off the firewall reinforcing plate while the left hand holes would be close enough to a bend in the metal so as to make tightening up the nuts pretty tough.

Thanks!

Share this post


Link to post
Share on other sites

Blue is serious - I can attest to his comment, "a great improvement" as we made this change to the larger booster on my Z (Jan. '71) a month ago.

Additionally, the switch is neither a long and/or difficult procedure when four hands go at it.

I think you will be pleased.

George

Share this post


Link to post
Share on other sites

As George says it was a great improvement. In fact I was glad we did it because enroute to ZCON on the I-95, George was behind me doing 65mph when some fools not far in front came to a complete stop. We both had to hammer the brakes very hard and both cars stopped safely. I don't think the other booster would have stopped as quickly.

For the drilling, just make a cardboard template to ensure it fits onto the new booster's stud holes and ensure it's outer edge is the same diameter.

btw we were able to do the work without removing the master cylinder from the brake lines. The only problem was losing the small clip on the clevis ..... a magnet on the side of a service light stole it from the drivers foot area/parts holder.

Share this post


Link to post
Share on other sites

I don't think the smaller boosters are available and I was talking to a rebuild shop about getting diaphragms to rebuild some of the boosters I have laying around. I don't think they have a source for the smaller diaphragms any more so hence no rebuilt little boosters...

Charles

Share this post


Link to post
Share on other sites

The difference between 7" and 8.5" diameter doesn't sound like much, but this is pizza math! A 7" circle has an area of 38.5 square inches, and the 8.5" circle has an area of 57 square inches, nearly 50% more area for air pressure to act upon!

Share this post


Link to post
Share on other sites

Further lack of progress with parts suppliers and the above helpful input are causing me to rethink a retrofit to the bigger booster. Interesting that Black Dragon lists a booster for '70-'71 and another one for '73-78. My guess is that the '72 model year spanned both boosters. The build date on my car is 12/71, so maybe it has the earlier (smaller diameter) booster.

Share this post


Link to post
Share on other sites

The new, larger booster is installed. I had to relocate all four holes out 1 cm and everything bolted up fine. It is a very tight fit between the clutch master cylinder and the bracket for the accelerator linkage with only about a couple of mm clearance on each side. You have to be very precise in drilling the holds, but they all landed on the pedal box interior to the firewall. I used some fender washers to hide the old holes on the inside. On the outside, the old holes are covered up by the larger booster.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.